Which protocol family is required prior to assigning an IP address to an interface?（）A、family ipB、family ip6C、family inetD、family inet4

共用题干
The Family
The structure of a family takes different forms around the world and even in the same society. The family's form changes as it adapts to changing social and economic influences. Until recently,the most common form in North America was the nuclear family,consisting of a married couple with their minor children. The nuclear family is an independent unit. It must be prepared to fend for itself. Individual family members strongly depend on one anoth-er. There is little help from outside the family in emergencies. Elderly relatives of a nuclear family are cared for only if it is possible for the family to do so. In North America,the elderly often do not live with the family;they live in retirement communities and nursing homes.
There are many parallels between the nuclear family in industrial societies,such as North America,and of families in societies such as that of the Inuits,who live in harsh environments. The nuclear family structure is well adapted to a life of mobility. In harsh condi-tions,mobility allows the family to hunt for food. For North Americans,the hunt for jobs and improved social status also requires mobility.
The nuclear family was not always the North American standard. In a more agrarian time,the small nuclear family was usually part of a larger extended family. This might have included grandparents,mother and father,brothers and sisters,uncles,aunts,and cousins. In North America today,there is a dramatic rise in the number of single-parent households. Twice as many households in the United States are headed by divorced,separated,or never-married individuals as are comprised of nuclear families. The structure of the family,not just in North America,but throughout the world,continues to change as it adapts to changing conditions.

Another good title for this passage would be______.
A: What Makes a Family?
B: The Life of the Inuits
C: Living With Hardship
D: The Failure of the Nuclear Family

We first think of the traditional or nuclear family．This is a two-generation family,the father and the mother and their own children．Most couples wanted to have four children,two boys,two girls.
Some nuclear families,however,may add one or more grandparents to come to live with them,that is three generations．This kind of family with grandparents,parents,and grandchildren is called an extended family．This family type was not very common during the later half of the twentieth century,but it's becoming more common now as an elderly grandparent moves in to live with a son or daughter．This is more possible now that American homes have become larger．What is interesting,however,is that after the grandchildren move out of the home and start their own families,this extended family shrinks back to a nuclear family,with just two generations again living together,a grandparent and parents,with the grandchildren coming only for occasional visits．
Now,the fatherless or motherless family is one kind of what we call a single-parent family．In the fatherless family it's just the mother and her children．As I said,this can be the result of the husband's death,of an unmarried mother,of a separation or divorce．There are also a growing number of motherless families--where the father raises the children,for any of the same reasons．A motherless family may also be fatherless,but still a family with one adult．This is becoming more common in the big cities where a grandmother will raise her daughter's children while the daughter goes elsewhere to work.
One other new kind of family is becoming increasingly more common．A single parent with one or more children will marry again．Perhaps the other parent is also a single parent．Together they will start what is called a blended family,which blends together or combines the children from two other families.

How is a blended family formed?

A.A blended family is formed by two single-parent familie
B.A blended family is formed by a nuclear family and a grandparen
C.A blended family is formed by a nuclear family and grandparent
D.A blended family is formed by two fatherless familie